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Heart Valves: Where They Are and What They Do

The Four Valves of the Human Heart

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Updated January 22, 2012

Heart Valves and Chambers

Human Heart, Chambers of the Heart and Heart Valves Image

Image: © ADAM

There are four heart valves in a healthy human heart. The valves help to maintain proper blood flow through the heart, keeping blood moving efficiently and smoothly, and in the right direction. In addition to the valves there are four heart chambers -- the upper chambers are called the left and right atrium, the lower chambers are the left and right ventricle.

A healthy heart valve will stop blood from flowing out of a heart chamber until it is time for the heart to pump the blood to its next destination. The valves open and close with precision timing, allowing the heart to pump blood effectively.

A valve that does not work properly will cause the heart to work much harder than it should, as blood tries to flow in the wrong direction. Blood may also “leak” through a diseased valve that is not functioning well.

The Tricuspid Heart Valve

The tricuspid valve is the first valve that blood flows through in the heart. It is one of two atrioventricular valves, meaning that it is located between the atrium and the ventricle, in this case, on the right side of the heart. It is made of three flaps, or leaflets, that work together to stop and start the flow of blood.

The leaflets are attached to tiny muscles, called the papillary muscles, that strengthen the movement of the leaflets. The tricuspid valve opens when the atrium contracts, allowing blood to flow into the ventricle.

The tricuspid valve, like the mitral valve, is one of the common sites of valve prolapse and regurgitation, conditions which may make medical intervention a necessity.

The Pulmonic Heart Valve

The pulmonic valve is the second valve of the heart. Like the aortic valve, it is also referred to as a semilunar valve, because of its shape. It lies between the right ventricle and the pulmonary artery, which takes blood to the lungs. When the right ventricle contracts, the tricuspid valve opens, allowing blood to flow to the lungs.

The Mitral Heart Valve

The mitral valve, or bicuspid valve, is the third valve of the heart. Like the tricuspid valve, it is an atrioventricular valve, meaning it rests between the left atrium and the left ventricle. Oxygenated blood passes through the mitral valve when the atrium contracts, allowing blood to flow from the upper chamber into the lower ventricle.

The mitral valve is composed of two leaflets, or flaps, that prevent blood from flowing into the ventricle too soon. When the atrium contracts, the mitral valve opens, allowing blood to move into the ventricle.

The mitral valve, like the tricuspid valve, is a common site of valve prolapse and regurgitation, conditions that may require medical intervention.

The Aortic Heart Valve

The aortic valve is the fourth and final heart valve, lying between the left ventricle and the aorta. The valve is composed of three leaflets, working together to stop blood from entering the aorta prematurely. The aortic valve opens when the ventricle contracts, allowing blood to move from the heart and start the journey to the rest of the body.

Heart Valve Problems

While some valves are more likely than others to develop specific valvular diseases, all of the valves can develop problems. In some cases, a valve problem will have no symptoms and will only be detected because of a heart murmur. Other problems, such as regurgitation, may present with symptoms such as shortness of breath or the sensation that the heart is working very hard.

If the problem is potentially serious, testing may be recommended to determine if valve repair surgery or valve replacement surgery should be considered.

For More Information About The Human Heart & Heart Surgery

Sources:

Heart Valves. The American Heart Association. Accessed March, 2009. http://www.heart.org/HEARTORG/Conditions/HeartAttack/PreventionTreatmentofHeartAttack/Heart-Valves-Explained_UCM_305656_Article.jsp

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